(a) Technical Field
The present disclosure relates to a motor control system and method for compensating disturbance, and more particularly, to a motor control system and method for compensating disturbance to reduce noise while providing an operation stability of a permanent magnet type synchronous motor.
(b) Background Art
The permanent magnet type synchronous motor in general may be controlled for three purposes, namely, a torque control using a current control, a speed control, and a position control. The torque control is a control procedure based on the speed control and the position control and in general is referred to as a current control since the current is in direct proportion to torque. The torque control, namely, a current control, is executed with a proportional-integral (PI) controller and a linear feedback control, but it is disadvantageous that control stability may be degraded due to disturbance such as a back-emf, etc. Any change in a magnetic flux induced by a stator when a permanent magnet rotates may interact with the current of a stator, thereby generating nonlinearity due to the back-emf. The nonlinearity may change a motor model or may be interpreted as disturbance.
The nonlinearity due to the disturbance such as the back-emf may be estimated using a parameter value of a motor circuit, the current, and a motor speed measurement, but a new design for a controller is still required for compensating disturbance. To compensate any effects of the back-emf, a feed-forward and a feedback control method are mainly being used in the conventional technology, but such a method is sensitive to any unexpected change in parameters, and requires accurate measurement of a motor speed.
The above information disclosed in this section is merely for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.